1. Field of the Invention
The present invention pertains to inkjet printing or more particularly to coating compositions and recording sheets composed of printable coating compositions on substrates which are useful for photographic quality prints by inkjet printing technology, such as thermal and piezo.
2. Description of the Related Art
Imaging techniques using inkjet printing systems are well known in the art. For example U.S. Pat. No. 4,592,954 describes basic inkjet printing techniques. U.S. Pat. No. 4,578,285 describes an inkjet printing method by ejecting ink droplets from a print head through one or more nozzles. Several schemes are utilized to control the deposition of the ink droplets to form desired characters and images. One method comprises deflecting electrically charged droplets by electrostatic means. Another method comprises the ejection of single droplets under the control of a piezoelectric device.
It has been a problem in the art to provide a recording sheet for inkjet printing which is receptive to inks, allows the ink to dry quickly without running or smearing, provides sharp image quality and has very good water and humidity resistance which deters curling. Many attempts have been made produce recording sheets for inkjet printing which have all of these properties simultaneously. In this regard U.S. Pat. No. 4,371,582 describes an inkjet recording sheet containing a basic latex polymer. U.S. Pat. No. 3,158,494 describes a polyurethane ink receptive surface. U.S. Pat. No. 5,693,410 describes an inkjet recording transparencies having two coatings, namely a heat dissipating, fire resistant coating in contact with a substrate and a second ink receiving coating layer on the first layer comprising a hydrophilic binder, an ink spreading agent, a cationic component, a light-fastness inducing agent, a filler and a biocide. JP Pat. 9,202,041 describes inkjet recording media which has good ink drying properties comprising a substrate provided with at least one ink receiving layer which contains a reaction product of polyalkylene oxide with an isocyanate and a water insoluble cellulose compound. While the above inkjet media are suitable for their intended purposes, there remains a need for a universal ink jet media for a dye based ink system as well as a pigment based ink system. Further, there is a need for a universal ink jet media useful for obtaining photographic quality prints by both thermal and piezo inkjet printing technologies. Additionally, there remains a need for coatings for inkjet media which have good water resistance which can counter media curl due to humidity changes.
The present invention provides inkjet printable coated media which overcome the above-noted disadvantages. The invention provides coating compositions, which when applied to suitable substrates such as transparent, translucent or opaque, white plastic films, paper or the like can achieve photographic quality prints by using any of a variety of inkjet printers. The coating composition is compatible with dye based and pigment based ink systems which can be printed both by thermal type inkjet printers and piezo type inkjet printers.